Substantial change toward a more Westernized lifestyle has taken place among younger individuals who were born after World War II (WWII) in non-Western countries including Japan. Data from national sample surveys in Japan clearly demonstrate that risk factor profiles for coronary heart disease (CHD) are very similar to those in the United States (US) in this post WWII cohort. Men in Japan do have a considerably higher prevalence of cigarette smoking and men in the US have a higher prevalence of obesity. CHD mortality among men in Japan is, however, still less than a half of that in the US. Careful review of mortality statistics confirms this. This difference remains unique among industrialized countries. The investigators propose to test the null hypothesis that there are no differences in the extent of atherosclerosis among Japanese men in Japan, Japanese American men in Hawaii, and US white and black men in this post WWII birth cohort. This project will be based on recent and ongoing successful Japan/US collaborations in the INTERMAP, INTERLIPID and Honolulu Heart Program studies including development of the first standardized US/Japan diet tables. We will examine 300 white men and 100 black men aged 40-49, randomly selected from Allegheny County, PA, 300 Japanese American men aged 40-49 from the population-based sample recruited from the offspring of the members of the Honolulu Heart Program cohort, and 300 Japanese men aged 40-49, randomly selected from Kusatsu City, Japan. The Japanese recruitment and examination has already been supported in Japan. The extent of atherosclerosis and risk factor profiles for CHD will be evaluated and compared, as well as the relationship of specific risk factors to the measures of atherosclerosis. The measures of subclinical disease proposed include calcium scores of coronary artery and aorta measured by electron beam computed tomography (EBCT) and carotid intima thickness measured by ultrasound. Other proposed measures include dietary intake by food frequency questionnaire, total cholesterol, LDLc, HDLc, lipids by NMR spectroscopy, blood pressure, cigarette smoking, thiocyanate, omega-3 fatty acid, alcohol consumption, body mass index (BMI), intra-abdominal fat, and others. Better understanding the reasons for the low Japanese rates may help us find new methods for prevention of CHD in all populations.